xref: /qemu/scripts/qapi/visit.py (revision cbe8f87f975264ee5b61795dc86f70915fb5f5f3) 
1"""
2QAPI visitor generator
3
4Copyright IBM, Corp. 2011
5Copyright (C) 2014-2018 Red Hat, Inc.
6
7Authors:
8 Anthony Liguori <aliguori@us.ibm.com>
9 Michael Roth    <mdroth@linux.vnet.ibm.com>
10 Markus Armbruster <armbru@redhat.com>
11
12This work is licensed under the terms of the GNU GPL, version 2.
13See the COPYING file in the top-level directory.
14"""
15
16from .common import (
17    c_enum_const,
18    c_name,
19    gen_endif,
20    gen_if,
21    indent,
22    mcgen,
23)
24from .gen import QAPISchemaModularCVisitor, ifcontext
25from .schema import QAPISchemaObjectType
26
27
28def gen_visit_decl(name, scalar=False):
29    c_type = c_name(name) + ' *'
30    if not scalar:
31        c_type += '*'
32    return mcgen('''
33
34bool visit_type_%(c_name)s(Visitor *v, const char *name,
35                 %(c_type)sobj, Error **errp);
36''',
37                 c_name=c_name(name), c_type=c_type)
38
39
40def gen_visit_members_decl(name):
41    return mcgen('''
42
43bool visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp);
44''',
45                 c_name=c_name(name))
46
47
48def gen_visit_object_members(name, base, members, variants):
49    ret = mcgen('''
50
51bool visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp)
52{
53''',
54                c_name=c_name(name))
55
56    if base:
57        ret += mcgen('''
58    if (!visit_type_%(c_type)s_members(v, (%(c_type)s *)obj, errp)) {
59        return false;
60    }
61''',
62                     c_type=base.c_name())
63
64    for memb in members:
65        ret += gen_if(memb.ifcond)
66        if memb.optional:
67            ret += mcgen('''
68    if (visit_optional(v, "%(name)s", &obj->has_%(c_name)s)) {
69''',
70                         name=memb.name, c_name=c_name(memb.name))
71            indent.increase()
72        ret += mcgen('''
73    if (!visit_type_%(c_type)s(v, "%(name)s", &obj->%(c_name)s, errp)) {
74        return false;
75    }
76''',
77                     c_type=memb.type.c_name(), name=memb.name,
78                     c_name=c_name(memb.name))
79        if memb.optional:
80            indent.decrease()
81            ret += mcgen('''
82    }
83''')
84        ret += gen_endif(memb.ifcond)
85
86    if variants:
87        ret += mcgen('''
88    switch (obj->%(c_name)s) {
89''',
90                     c_name=c_name(variants.tag_member.name))
91
92        for var in variants.variants:
93            case_str = c_enum_const(variants.tag_member.type.name,
94                                    var.name,
95                                    variants.tag_member.type.prefix)
96            ret += gen_if(var.ifcond)
97            if var.type.name == 'q_empty':
98                # valid variant and nothing to do
99                ret += mcgen('''
100    case %(case)s:
101        break;
102''',
103                             case=case_str)
104            else:
105                ret += mcgen('''
106    case %(case)s:
107        return visit_type_%(c_type)s_members(v, &obj->u.%(c_name)s, errp);
108''',
109                             case=case_str,
110                             c_type=var.type.c_name(), c_name=c_name(var.name))
111
112            ret += gen_endif(var.ifcond)
113        ret += mcgen('''
114    default:
115        abort();
116    }
117''')
118
119    ret += mcgen('''
120    return true;
121}
122''')
123    return ret
124
125
126def gen_visit_list(name, element_type):
127    return mcgen('''
128
129bool visit_type_%(c_name)s(Visitor *v, const char *name,
130                 %(c_name)s **obj, Error **errp)
131{
132    bool ok = false;
133    %(c_name)s *tail;
134    size_t size = sizeof(**obj);
135
136    if (!visit_start_list(v, name, (GenericList **)obj, size, errp)) {
137        return false;
138    }
139
140    for (tail = *obj; tail;
141         tail = (%(c_name)s *)visit_next_list(v, (GenericList *)tail, size)) {
142        if (!visit_type_%(c_elt_type)s(v, NULL, &tail->value, errp)) {
143            goto out_obj;
144        }
145    }
146
147    ok = visit_check_list(v, errp);
148out_obj:
149    visit_end_list(v, (void **)obj);
150    if (!ok && visit_is_input(v)) {
151        qapi_free_%(c_name)s(*obj);
152        *obj = NULL;
153    }
154    return ok;
155}
156''',
157                 c_name=c_name(name), c_elt_type=element_type.c_name())
158
159
160def gen_visit_enum(name):
161    return mcgen('''
162
163bool visit_type_%(c_name)s(Visitor *v, const char *name,
164                 %(c_name)s *obj, Error **errp)
165{
166    int value = *obj;
167    bool ok = visit_type_enum(v, name, &value, &%(c_name)s_lookup, errp);
168    *obj = value;
169    return ok;
170}
171''',
172                 c_name=c_name(name))
173
174
175def gen_visit_alternate(name, variants):
176    ret = mcgen('''
177
178bool visit_type_%(c_name)s(Visitor *v, const char *name,
179                 %(c_name)s **obj, Error **errp)
180{
181    bool ok = false;
182
183    if (!visit_start_alternate(v, name, (GenericAlternate **)obj,
184                               sizeof(**obj), errp)) {
185        return false;
186    }
187    if (!*obj) {
188        /* incomplete */
189        assert(visit_is_dealloc(v));
190        ok = true;
191        goto out_obj;
192    }
193    switch ((*obj)->type) {
194''',
195                c_name=c_name(name))
196
197    for var in variants.variants:
198        ret += gen_if(var.ifcond)
199        ret += mcgen('''
200    case %(case)s:
201''',
202                     case=var.type.alternate_qtype())
203        if isinstance(var.type, QAPISchemaObjectType):
204            ret += mcgen('''
205        if (!visit_start_struct(v, name, NULL, 0, errp)) {
206            break;
207        }
208        if (visit_type_%(c_type)s_members(v, &(*obj)->u.%(c_name)s, errp)) {
209            ok = visit_check_struct(v, errp);
210        }
211        visit_end_struct(v, NULL);
212''',
213                         c_type=var.type.c_name(),
214                         c_name=c_name(var.name))
215        else:
216            ret += mcgen('''
217        ok = visit_type_%(c_type)s(v, name, &(*obj)->u.%(c_name)s, errp);
218''',
219                         c_type=var.type.c_name(),
220                         c_name=c_name(var.name))
221        ret += mcgen('''
222        break;
223''')
224        ret += gen_endif(var.ifcond)
225
226    ret += mcgen('''
227    case QTYPE_NONE:
228        abort();
229    default:
230        assert(visit_is_input(v));
231        error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
232                   "%(name)s");
233        /* Avoid passing invalid *obj to qapi_free_%(c_name)s() */
234        g_free(*obj);
235        *obj = NULL;
236    }
237out_obj:
238    visit_end_alternate(v, (void **)obj);
239    if (!ok && visit_is_input(v)) {
240        qapi_free_%(c_name)s(*obj);
241        *obj = NULL;
242    }
243    return ok;
244}
245''',
246                 name=name, c_name=c_name(name))
247
248    return ret
249
250
251def gen_visit_object(name, base, members, variants):
252    return mcgen('''
253
254bool visit_type_%(c_name)s(Visitor *v, const char *name,
255                 %(c_name)s **obj, Error **errp)
256{
257    bool ok = false;
258
259    if (!visit_start_struct(v, name, (void **)obj, sizeof(%(c_name)s), errp)) {
260        return false;
261    }
262    if (!*obj) {
263        /* incomplete */
264        assert(visit_is_dealloc(v));
265        ok = true;
266        goto out_obj;
267    }
268    if (!visit_type_%(c_name)s_members(v, *obj, errp)) {
269        goto out_obj;
270    }
271    ok = visit_check_struct(v, errp);
272out_obj:
273    visit_end_struct(v, (void **)obj);
274    if (!ok && visit_is_input(v)) {
275        qapi_free_%(c_name)s(*obj);
276        *obj = NULL;
277    }
278    return ok;
279}
280''',
281                 c_name=c_name(name))
282
283
284class QAPISchemaGenVisitVisitor(QAPISchemaModularCVisitor):
285
286    def __init__(self, prefix):
287        super().__init__(
288            prefix, 'qapi-visit', ' * Schema-defined QAPI visitors',
289            ' * Built-in QAPI visitors', __doc__)
290
291    def _begin_system_module(self, name):
292        self._genc.preamble_add(mcgen('''
293#include "qemu/osdep.h"
294#include "qapi/error.h"
295#include "qapi/qapi-builtin-visit.h"
296'''))
297        self._genh.preamble_add(mcgen('''
298#include "qapi/visitor.h"
299#include "qapi/qapi-builtin-types.h"
300
301'''))
302
303    def _begin_user_module(self, name):
304        types = self._module_basename('qapi-types', name)
305        visit = self._module_basename('qapi-visit', name)
306        self._genc.preamble_add(mcgen('''
307#include "qemu/osdep.h"
308#include "qapi/error.h"
309#include "qapi/qmp/qerror.h"
310#include "%(visit)s.h"
311''',
312                                      visit=visit))
313        self._genh.preamble_add(mcgen('''
314#include "qapi/qapi-builtin-visit.h"
315#include "%(types)s.h"
316
317''',
318                                      types=types))
319
320    def visit_enum_type(self, name, info, ifcond, features, members, prefix):
321        with ifcontext(ifcond, self._genh, self._genc):
322            self._genh.add(gen_visit_decl(name, scalar=True))
323            self._genc.add(gen_visit_enum(name))
324
325    def visit_array_type(self, name, info, ifcond, element_type):
326        with ifcontext(ifcond, self._genh, self._genc):
327            self._genh.add(gen_visit_decl(name))
328            self._genc.add(gen_visit_list(name, element_type))
329
330    def visit_object_type(self, name, info, ifcond, features,
331                          base, members, variants):
332        # Nothing to do for the special empty builtin
333        if name == 'q_empty':
334            return
335        with ifcontext(ifcond, self._genh, self._genc):
336            self._genh.add(gen_visit_members_decl(name))
337            self._genc.add(gen_visit_object_members(name, base,
338                                                    members, variants))
339            # TODO Worth changing the visitor signature, so we could
340            # directly use rather than repeat type.is_implicit()?
341            if not name.startswith('q_'):
342                # only explicit types need an allocating visit
343                self._genh.add(gen_visit_decl(name))
344                self._genc.add(gen_visit_object(name, base, members, variants))
345
346    def visit_alternate_type(self, name, info, ifcond, features, variants):
347        with ifcontext(ifcond, self._genh, self._genc):
348            self._genh.add(gen_visit_decl(name))
349            self._genc.add(gen_visit_alternate(name, variants))
350
351
352def gen_visit(schema, output_dir, prefix, opt_builtins):
353    vis = QAPISchemaGenVisitVisitor(prefix)
354    schema.visit(vis)
355    vis.write(output_dir, opt_builtins)
356